Memory-related EEG power and coherence reductions in mild Alzheimer's disease.

OBJECTIVES: To examine memory-related EEG power and coherence over temporal and central recording sites in patients with early Alzheimer's disease (AD) and normal controls. METHOD: EEG was recorded from central (Fz, Cz and Pz) and temporal (T3 and T4) electrodes while ten very mild AD patients and ten controls performed a Sternberg-type memory scanning task with three levels of working memory load. Spectral power in delta (0-3 Hz), theta (3-5 Hz), lower alpha1 (5-7 Hz), lower alpha2 (7-9 Hz), upper alpha (9-11 Hz) and beta (15-30 Hz) was averaged for temporal and central electrodes. Coherence was averaged between central electrodes, between central and right temporal electrodes and between central and left temporal electrodes. RESULTS: While behavioral performance of very mild AD patients did not differ significantly from that of normal controls, findings suggest that normal controls but not AD patients respond to memory demands by increasing upper alpha power over temporal cortex. When compared with normal controls, AD patients had reduced upper alpha coherence between central and right temporal cortex. DISCUSSION: Results are consistent with previous research on the role of upper alpha in semantic memory and suggest that very mild AD may inhibit selective synchronization of upper alpha in temporal lobes. Reduced coherence between central and temporal cortex is discussed in light of a neurological model of AD that hypothesizes reduced electrocortical efficiency and a breakdown of neural network communication to temporal lobes possibly resulting from temporal lobe atrophy.     

Temporal information for spatially constrained locomotion

How is locomotion adapted to spatial environmental constraints? The control of this everyday behavior is claimed to be based on information that specifies either spatial or temporal properties of the actor-environment system. Although studies on open-loop locomotor pointing (i.e., the positioning of a foot on a target on the floor while walking) agree on the use of spatial information, studies on closed-loop locomotor pointing propose the use of temporal information. Here, we test the hypothesis of closed-loop locomotor pointing based on temporal information, by dissociating spatial and temporal information in a virtual reality setup (virtual environment connected to a treadmill). The results support this hypothesis and shed some light on the type of temporal information that is used. The performed dissociation between spatial and temporal information, however, does not rule out a control based on a continuous updating of spatial information. Therefore, our conclusion on the use of temporal information was moderated.     

面神经颞支的应用解剖

目的确定面神经颞支的数量、走行和分布情况,为涉及面侧区和颞区的美容外科手术提供解剖学资料。方法解剖33具(66侧)成人尸体标本,探明颞支支数及走行;测量面神经颞支各分支越过颧弓下缘、外眦角等部位的距离。结果面神经颞支有4个分支,分别称为颞支Ⅰ、Ⅱ、Ⅲ、Ⅳ。除颞支Ⅳ经腮腺前缘浅出外,其余均经上缘浅出。浅出后它们立即到达颧弓浅面,其中颞支Ⅰ主要发支到达额肌深面;颞支Ⅱ主要到达额肌与眼轮匝肌交界部深面。颞支Ⅲ、Ⅳ主要发支到达眼轮匝肌深面。测量得到面神经颞支各分支越过颧弓下缘处距外眦角的距离男性分别为3.8cm、3.5cm、2.9cm、和2.8cm;女性分别为3.6cm、3.3cm、2.7cm、2.6cm。面神经颞支各分支发出部位距颧弓下缘的距离男性分别为3.0cm、3.8cm、4.0cm、4.2cm;女性分别为2.7cm、3.3cm、3.3cm、3.7cm。结论面神经颞支根据性别具有基本确定的走行及分布,为相关的美容外科手术提供了解剖学依据。     

Spatio-temporal (2D+T) non-rigid registration of real-time 3D echocardiography and cardiovascular MR image sequences

In this paper we describe a method to non-rigidly co-register a 2D slice sequence from real-time 3D echocardiography with a 2D cardiovascular MR image sequence. This is challenging because the imaging modalities have different spatial and temporal resolution. Non-rigid registration is required for accurate alignment due to imprecision of cardiac gating and natural motion variations between cardiac cycles. In our approach the deformation field between the imaging modalities is decoupled into temporal and spatial components. First, temporal alignment is performed to establish temporal correspondence between a real-time 3D echocardiography frame and a cardiovascular MR frame. Spatial alignment is then performed using an adaptive non-rigid registration algorithm based on local phase mutual information on each temporally aligned image pair. Experiments on seven volunteer datasets are reported. Evaluation of registration errors based on expert-identified landmarks shows that the spatio-temporal registration algorithm gives a mean registration error of 3.56 ± 0.49 and 3.54 ± 0.27 mm for the short and long axis sequences, respectively.     

Memory for single items,word pairs,and temporal order of different kinds in a patient with selective hippocampal lesions

One kind of between-list and two kinds of within-list temporal order memory were examined in a patient with selective bilateral hippocampal lesions. This damage disrupted memory for all three kinds of temporal order memory, but left item and word pair recognition relatively intact. These findings are inconsistent with claims that (1) hippocampal lesions, like those of the medial temporal lobe (MTL) cortex, disrupt item and word pair recognition, and that (2) hippocampal lesions disrupt temporal order memory and item recognition to the same degree. Not only was word pair recognition intact in the patient, but further evidence indicates that her recognition of other associations between items of the same kind is also spared so retrieval of such associations cannot be sufficient to support within-list temporal order recognition. Rather, as other evidence indicates that the patient is impaired at recognition of associations between different kinds of information, within-list (and possibly between-list) temporal order memory may be impaired by hippocampal lesions because it critically depends on retrieving associations between different kinds of information.     

Association between temporal orientation and attitudes about BRCA1/2 testing among women of African descent with family histories of breast cancer

OBJECTIVE: Previous studies have identified specific attitudes (pros and cons) about BRCA testing held by women of African descent that are associated with decisions to participate in testing. These testing attitudes may be determined, in part, by temporal orientation, or how one perceives the significance of events and the consequences of their actions in terms of past, present, and future. The current study explored the relationship between temporal orientation and pros and cons of BRCA testing among 140 women of African descent with a family history suggestive of a genetic mutation predisposing to breast cancer. METHODS: Participants completed measures of temporal orientation and genetic testing attitudes. RESULTS: Multivariate analyses indicated that future orientation was positively associated with perceived pros of testing. Additional analyses revealed significant associations between temporal orientation and specific item subsets related to the negative and positive impact of testing on family and personal control over one's health. CONCLUSION: These results support an association between temporal orientation and attitudes about BRCA testing among women of African descent with family histories of breast cancer. PRACTICE IMPLICATIONS: Findings support exploration of temporal orientation in future research on BRCA testing decisions among women of African descent and this construct's importance in developing decision aids and tailoring genetic counseling.     

Memory for single items, word pairs, and temporal order of different kinds in a patient with selective hippocampal lesions

One kind of between-list and two kinds of within-list temporal order memory were examined in a patient with selective bilateral hippocampal lesions. This damage disrupted memory for all three kinds of temporal order memory, but left item and word pair recognition relatively intact. These findings are inconsistent with claims that (1) hippocampal lesions, like those of the medial temporal lobe (MTL) cortex, disrupt item and word pair recognition, and that (2) hippocampal lesions disrupt temporal order memory and item recognition to the same degree. Not only was word pair recognition intact in the patient, but further evidence indicates that her recognition of other associations between items of the same kind is also spared so retrieval of such associations cannot be sufficient to support within-list temporal order recognition. Rather, as other evidence indicates that the patient is impaired at recognition of associations between different kinds of information, within-list (and possibly between-list) temporal order memory may be impaired by hippocampal lesions because it critically depends on retrieving associations between different kinds of information.     

Development and temporal organization of repetitive behavior in an animal model

Despite repetitive behaviors being a common feature of a number of clinical disorders and ubiquitous in normative development, little attention has been given to their ontogeny or temporal dynamics. We characterized these features in a mouse model of repetitive behavior to identify discrete trajectories of development and developmental changes in temporal dynamics. Three qualitatively distinct trajectory groups were identified which allowed for an examination of the interaction between temporal organization and developmental trajectory. Significant differences in temporal dynamics were found across development and among trajectory groups. Significant interactions of trajectory group and developmental period on temporal organization were also found. The combination of group‐based trajectory modeling and a novel method for analysis and graphic depiction of temporal organization allowed for the exploration of the interplay between these two fundamental behavioral processes. Such methods may be useful tools in the assessment and treatment of repetitive behavior in clinical populations. © 2010 Wiley Periodicals, Inc. Dev Psychobiol 52: 813–824, 2010.     

Neuropathology with clinical correlations of sporadic amyotrophic lateral sclerosis: 102 autopsy cases examined between 1962 and 2000

Sporadic amyotrophic lateral sclerosis (ALS) is a fatal neurological disorder affecting adults. We studied the neuropathology and clinical correlations in 102 autopsy cases of ALS. The age at onset of the disease was significantly higher for the bulbaronset form (30 cases) than for the limb-onset form (72 cases). Dementia was confirmed in 7 cases. These 102 cases were divided into 4 pathological subgroups: typical ALS (59 cases), lower-motor-predominant ALS (23 cases), ALS with temporal lesions (18 cases), and ALS with pallido-nigro-luysian degeneration (2 cases). The age at onset was significantly higher for lower-motor-predominant ALS and ALS with temporal lesions than for typical ALS. In the lower motor neurons, Bunina bodies were detected in 88 cases, whereas ubiquitin-immunoreactive skein and/or spherical inclusions were detected in all 102 cases. Of the 100 available cases, 50 and 16 also showed ubiquitin-immunoreactive inclusions in the neostriatal and temporal small neurons, respectively. Ubiquitin-immunoreactive dystrophic neurites were also observed in the neostriatum in 3 of the 50 cases with neostriatal inclusions, and in the temporal cortex in 4 of the 16 cases with temporal inclusions. There was a significant association between the bulbar-onset form, temporal lesions, neostriatal inclusions and temporal inclusions, and between dementia, temporal lesions and temporal inclusions. Neostriatal and temporal dystrophic neurites were associated with dementia and bulbar-onset form through temporal lesions and temporal inclusions. The present findings may be helpful for designing further studies on the mechanisms underlying the development of ALS.     

Visual presentation of hand image modulates visuo–tactile temporal order judgment

Perceptual systems can distinguish among a variety of inputs in the temporal domain, including even different sensory inputs. This process has been investigated mainly by using a temporal task (temporal order judgment: TOJ). For example, studies have reported estimated critical limits (just noticeable difference: JND) of the TOJ between a visual stimulus and a tactile stimulus (visuo–tactile TOJ, e.g., flashes and vibrations) fell within a certain temporal range. Recent studies have also suggested that the visual presentation of a hand image could modulate visuo–tactile integrations in the temporal domain, but these studies did not thoroughly examine such effects by using temporal tasks. Here, we investigated the effect of visual presentation of a hand image on visuo–tactile TOJ. In our experiments, a visual stimulus was presented on the index finger of a hand image and a tactile stimulus was presented on the index finger of a participant’s hand. We found that the JND of visuo–tactile TOJ became larger when a forward hand image was presented than when inverted hand or arrow images were presented. However, this effect was not observed for the TOJ between an auditory stimulus and a visual stimulus. Thus, the visual presentation of a hand image whose angle corresponds to that of one’s own hand could selectively degrade visuo–tactile TOJ. This finding indicates that visual hand images implicitly enhance the internal proximity between the visual and tactile stimuli and make them difficult to distinguish from each other in the temporal domain.     

耳颞部矢状塑化薄片与HRCT图像对照研究

目的 探讨耳颞部重要结构在矢状断面上的形态规律及影像学表现，为该区影像诊断及外科手术提供形态学依据。方法 取6例成人耳颞部组织块，应用生物塑化技术制作成层厚1．2mm的矢状位连续薄层断面标本，并与对应的HRCT图像进行对照。结果 塑化薄层断面与HRCT图像有良好的对应关系。矢状断面可良好显示颞骨结构及其周围结构的毗邻关系，对面神经鼓室段及垂直段、前庭导水管等结构显示尤佳。结论 耳颞部矢状面扫描是补充横、冠状面扫描缺陷的一个重要扫描方法。结合塑化薄片、HRCT进行对照研究，可深入了解耳颞部矢状断面的解剖结构，为耳颞部疾病的影像学诊断和临床手术提供翔实准确的断层形态资料。     

Towards a comprehensive treatment of repetitions, periodicity and temporal constraints in clinical guidelines

OBJECTIVE: In this paper, we define a principled approach to represent temporal constraints in clinical guidelines and to reason (i.e., perform inferences in the form of constraint propagation) on them. We consider different types of constraints, including composite and repeated actions, and propose different types of temporal functionalities (e.g., temporal consistency checking). BACKGROUND: Constraints about actions, durations, delays and periodic repetitions of actions are an intrinsic part of most clinical guidelines. Although several approaches provide expressive temporal formalisms, only few of them deal with the related temporal reasoning issues. METHODOLOGY: We first propose a temporal representation formalism and two temporal reasoning algorithms. Then, we consider the trade-off between the expressiveness of the formalism and the computational complexity of the algorithms, in order to devise a correct, complete and tractable approach. Finally, we show how the algorithms can be exploited to provide clinical guideline systems with different types of temporal facilities. RESULTS: Our approach offers several advantages. During the guideline acquisition phase, it enables to represent temporal constraints, and to check their consistency. In the execution phase, it checks the consistency between the execution times of the actions and the constraints in the guidelines, and provides query answering and simulation facilities.     

Seashore Rhythm Test performance in patients with unilateral temporal lobe damage

The Seashore Rhythm Test has been reported to be sensitive to right hemisphere dysfunction and, in particular, right temporal lobe integrity. However, several reports have appeared that have failed to support these earlier findings. In the latter studies, the confounding effects of possible bilateral or extratemporal lobe dysfunction in the patient groups could not be ruled out. The present study investigated the Seashore Rhythm Test performance of 38 right-handed seizure patients with evidence of glucose hypometabolism restricted to the right (n = 23) or left (n = 15) temporal lobe on positron computed tomography. Patients were studied prior to and subsequent to unilateral anterior temporal lobectomy for control of medically intractable seizures. No significant difference was found between right and left temporal lobe dysfunctional patients, either pre- or post-lobectomy, which further corroborates that the Seashore Rhythm Test does not discriminate between patients with right vs. left temporal lobe damage.     

Distinct time scales in cortical discrimination of natural sounds in songbirds

Understanding how single cortical neurons discriminate between sensory stimuli is fundamental to providing a link between cortical neural responses and perception. The discrimination of sensory stimuli by cortical neurons has been intensively investigated in the visual and somatosensory systems. However, relatively little is known about discrimination of sounds by auditory cortical neurons. Auditory cortex plays a particularly important role in the discrimination of complex sounds, e.g., vocal communication sounds. The rich dynamic structure of such complex sounds on multiple time scales motivates two questions regarding cortical discrimination. How does discrimination depend on the temporal resolution of the cortical response? How does discrimination accuracy evolve over time? Here we investigate these questions in field L, the analogue of primary auditory cortex in zebra finches, analyzing temporal resolution and temporal integration in the discrimination of conspecific songs (songs of the bird's own species) for both anesthetized and awake subjects. We demonstrate the existence of distinct time scales for temporal resolution and temporal integration and explain how they arise from cortical neural responses to complex dynamic sounds.     

Temporal constraints on interactions across kinaesthetic channels

We investigated the effect of correlation in background noise on the ability of participants to detect a kinaesthetic target on the index fingers of their hands. Participants had to judge whether the target (a smoothed ramp with quarter-sine onset and offset), was on the left or right finger (experiments 1 and 2). These targets were embedded in noise generated by pseudo-random up-down movements of both the left and right fingers. Positive correlation between the noise on the left and right fingers aided discrimination of the target signal relative to when the noise was uncorrelated. However, this benefit of positive correlation was subject to temporal limitations and diminished with increasing lag between the noise on the fingers (experiment 2). Tests of explicit detection of correlation in kinaesthetic noise (experiment 3) showed a similar pattern, with detection of correlation decreasing with the temporal lag between the noise on the fingers. The results suggest that kinaesthetic signal detection involves sensory integration across the fingers within a limited temporal window.     

Spatial and temporal acuity of visual perception can be enhanced selectively by attentional set

The aim of this research was to study the relationship between perceptual judgments about space and time. If spatial and temporal judgments were dissociable, they should be modulated selectively by attention. We compared the effect of the attentional set upon fine-grained spatial versus temporal discrimination of visual perception in two experiments. Using identical sensory stimulation, we measured perceptual judgments on either the size of a small spatial gap or the duration of a brief temporal gap. The attentional set was manipulated by cuing the task that was most likely to be performed. In one experiment, a neutral cue was also used, to measure relative benefits and costs of spatial and temporal task sets. If the attentional set could be directed selectively to spatial and temporal task-relevant dimensions, performance on both spatial and temporal acuity tasks should be specifically modulated by task cuing. The results showed that the attentional set enhanced the speed and accuracy of perceptual judgments similarly on both spatial and temporal tasks. Moreover, accuracy in one task was selectively enhanced by attending to that task while remaining unaffected by attending to the alternative task. This finding suggests multiple mechanisms, by which visual processing of spatial and temporal features can be selectively prepared without interfering with one another.     

Effects of spatial,temporal and spatiotemporal cueing are alike when attention is directed voluntarily

Visual cues that allow predicting location and onset of a stimulus facilitate orienting. In a seminal study, Coull and Nobre (J Neurosci 18:7426–7435, 1998) adapted the spatial cueing paradigm to investigate temporal orienting. Recent research in the spatial domain suggests though that the cues used in the spatial and temporal conditions were not comparable. In the spatial condition predictive arrow cues engaged involuntary and voluntary attention, in the temporal condition line width cues elicited voluntary attention shifts. A valid comparison between attentional modalities on the behavioural and neurophysiological level requires though that cues differ only with respect to attentional modality (spatial, temporal) and not in other aspects. To develop cues that are comparable and to assess spatial and temporal orienting, new line width cues for spatial and temporal orienting were devised that both engage only voluntary attention, and the results were compared to the cues used by Coull and Nobre (J Neurosci 18:7426–7435, 1998). Further, catch trials were included to counteract reorienting at the late time interval to promote comparisons between spatial and temporal data at that interval. The results showed that the outcome of the comparison between spatial, temporal and spatiotemporal orienting depended on the type of cue that was used and hence the type of attention that was engaged in each condition. The results indicated that orienting is equally effective in space and in time when attention is directed voluntarily. The new cues employed here can easily be used for future studies to assess underlying brain mechanisms.     

Forward and reverse hippocampal place-cell sequences during ripples

We report that temporal spike sequences from hippocampal place neurons of rats on an elevated track recurred in reverse order at the end of a run, but in forward order in anticipation of the run, coinciding with sharp waves. Vector distances between the place fields were reflected in the temporal structure of these sequences. This bidirectional re-enactment of temporal sequences may contribute to the establishment of higher-order associations in episodic memory.     

Callosotomy patients exhibit temporal uncoupling during continuous bimanual movements

Rhythmic bimanual movements are highly constrained in the temporal domain, with the gestures of the two hands tightly synchronized. Previous studies have implicated a subcortical locus for temporal coupling based on the observation that these constraints persist in callosotomy patients. We now report that such coupling is restricted to movements entailing a discrete event (such as a movement onset). Three callosotomy patients exhibited a striking lack of temporal coupling during continuous movements, with the two hands oscillating at non-identical frequencies. We propose a subcortical locus of temporal coupling for movements involving discrete events. In contrast, synchronization between the hands during continuous movements depends on interhemispheric transmission across the corpus callosum.     

带颞浅血管颅骨瓣修复颌面部缺损的应用解剖

目的：为带颞浅血管蒂颅骨外板骨瓣转位修复颌面部缺损提供解剖学基础。方法：在30侧经动脉灌注乳胶的成人尸体标本和8头颈铸型标本（5例保留骨骼）上,对颞浅动脉的走行、分支及分布进行观测,并在标本上进行模拟术式设计。结果：颞浅动脉起自颈外动脉,于外耳门前方越过颧弓根部浅出至皮下,在皮下组织和颞浅筋膜之间向前上走行,至颧弓上方分为额、顶二终支,其分支营养颅顶部大至3/4区域的软组织、骨膜和颅骨外板,颞浅动脉主干及额支、顶支动脉外径均大于1mm,浅出部位至颞线处可游离长度为8cm以上。结论：设计以颞浅动脉为蒂颅骨外板骨瓣转位修复颌面部缺损具有可行性。